1. Field of the Invention.
The present invention relates to a portable progressive and intermittent traction machine and, more particularly, to an electrically powered device for providing traction to a patient, intermittently or statically, between defined maximum and minimum force levels, and with a progressively increased force.
2. Description of the Prior Art.
In the field of physical therapy, traction has been used to eliminate patient pain and immobility of cervical, pelvic, arm, shoulder, leg, ankle, and neck joints, and related muscular disorders. Initially, traction was applied continuously, using a system of weights. Continuous traction assures a certain amount of immobilization of the joint and relieves muscle spasms. If correctly applied, it can achieve the desired result.
In the conventional method of application, the traction force level must be kept relatively low because the patient simply cannot tolerate high force levels for a long period of time. As a result, the conventional amount of weight that is used often does nothing more than to keep the patient still to some extent.
To overcome this problem, it has been proposed to use motorized intermittent traction to supplant all other methods of traction application. Intermittent traction relieves muscle spasms and has a massage-like affect upon the muscles and the ligamentous and capsular structures. It reduces swelling and promotes better circulation in the tissues. It prevents the formation of adhesions between the dural sleeves of the nerve roots and the adjacent capsular structures. Most importantly, with an intermittent force, the patient can tolerate a much higher force level and a better and faster result is achieved.
In order to provide intermittent traction, a number of portable intermittent traction machines have been designed, each of which including a cord and means for applying a force thereto for an amount of time set by a master timer. The machine typically can be operated in either a static or an intermittent mode. In the static mode, the force is increased to a set maximum force level where it is maintained for the time set in the master timer. In the intermittent mode, the force is alternately applied and released, the hold time and the rest time being independently set by separate timers.
Such known types of portable intermittent or static traction machines do not provide the full range of flexibility required to achieve the desired results in all cases. That is, the patient simply might not be capable of tolerating the full traction force at one time. Thus, it would be desirable to be able to progressively increase the force and to hold the force at each progressive level for a period of time before the force is again increased. Furthermore, in many cases, it is not necessary to completely reduce the force to zero on alternate cycles of an intermittent traction mode. Rather, it might be more appropriate to have the force alternate between a high and low, non-zero force level. Furthermore, the intermittent mode might also be combined with the progressive mode under many circumstances. A machine for operating in this manner has been unavailable heretofore.
Still further, existing machines do not provide a visual indication of the traction force being applied. They also do not include mechanisms for accurately controlling the force levels.